diff --git a/setup.py b/setup.py
index 75cd1e2..e7deae4 100644
--- a/setup.py
+++ b/setup.py
@@ -26,7 +26,7 @@
     install_requires=[
         'Twisted >= 12.1.0',
         'wokkel == 0.7.1',
-        'pyOpenSSL == 0.13',
+        'pyOpenSSL == 17.5.0',
     ],
 
     keywords='twisted',